1. Field of the Invention
The present invention relates to a mobile terminal, and more particularly, to a method for allocating an Internet Protocol (IP) address to an Internet-accessible mobile terminal.
2. Discussion of the Related Art
In general, a Dynamic Host Configuration Protocol (DHCP) is widely used for allocating an IP address for a mobile terminal.
The DHCP allows a DHCP server to allocate an IP address to a subscriber's mobile terminal dynamically, not fixedly.
FIG. 1 is a flowchart illustrating a conventional IP address allocation process between a mobile terminal and a DHCP server.
Referring to FIG. 1, a mobile terminal 10 broadcasts a DHCP DISCOVER message to a plurality of DHCP servers through a base station such that it is allocated an IP address for access to the mobile Internet (S1).
If any one 20 of the DHCP servers receives the DHCP DISCOVER message from the mobile terminal 10 through the base station, it transmits a DHCP OFFER message (including an IP address and parameters), which is a reply message to the DHCP DISCOVER message, to the mobile terminal 10 (S2).
The mobile terminal 10 receives the DHCP OFFER message transmitted from the DHCP server 20 and transmits a DHCP REQUEST message requesting allocation of the IP address included in the received DHCP OFFER message to the DHCP server 20 through the base station (S3).
The DHCP server 20 receives the DHCP REQUEST message, allocates the IP address to the mobile terminal 10, and transmits, to the mobile terminal 10, a DHCP ACK message notifying that the IP address allocation has been successfully performed (S4).
In the IP address allocation process, as mentioned above, the mobile terminal 10 gets the IP address from the DHCP server 20 through all procedures defined in the DHCP standard.
However, in order to get an IP address, a mobile terminal has to, for every allocation, search a plurality of DHCP servers to find one for providing the IP address.
Further, the searched DHCP server must search for an IP address whenever the mobile terminal requests an IP address allocation, resulting in a lengthy period of time being required for the IP address allocation, thus making it impossible to rapidly provide a mobile Internet service to the user.